The present invention relates to a substrate processing method and processing apparatus for cleaning a laser mark formed on a substrate such as a semiconductor wafer.
For example, a semiconductor device manufacturing process has a step where a semiconductor wafer must be cleaned at a high cleaning degree. Methods of cleaning a semiconductor wafer include the dip method of dipping a plurality of semiconductor wafers in a cleaning solution at once and the single wafer processing method of cleaning semiconductor wafers one by one by spraying a cleaning solution toward each semiconductor wafer. Recently, the single wafer processing method is often employed as it provides a high cleaning degree and it is advantageous in terms of cost when the semiconductor wafers are to be processed in a small lot.
As an example of the single wafer processing method, a cleaning apparatus which cleans the semiconductor wafer by using a cleaning tool such as a roll brush or disk brush is known. In this case, not only the roll brush or disk brush is rotated, but also the semiconductor wafer is rotated, so the brush comes into contact with the semiconductor wafer uniformly, thereby increasing the cleaning effect.
A semiconductor wafer has a laser mark, such as ID mark or lot No., in which information specific to the semiconductor wafer is marked with a laser beam. When a laser mark is marked on the semiconductor wafer with a laser beam, it forms a recess with a depth of about 20 xcexcm to 50 xcexcm.
Hence, a foreign substance is sometimes deposited in the recess of the laser mark. Particularly, since CMP (Chemical and Mechanical Polishing) is performed recently to cope with an increase in the number of wiring layers, a polishing agent used for this is inevitably deposited in the laser mark.
Conventionally, contamination deposited in the recess of the laser mark is not particularly cleaned out. If the surface of the semiconductor wafer is cleaned merely with the roll brush or disk brush, although the surface of the semiconductor wafer can be cleaned, contamination resulted from the polishing agent deposited in the recess of the laser mark cannot be cleaned out and removed. This contamination can cause a rejected article.
The present invention provides a substrate processing method and processing apparatus capable of cleaning out and removing contamination deposited in a laser mark formed on a substrate.
According to an aspect of the present invention, there is provided, in a substrate processing method of cleaning a laser mark formed on a surface of a substrate, characterized by comprising the steps of
holding the substrate and rotating the substrate in a circumferential direction,
detecting a laser mark formed on the substrate in a non-contact manner, and
controlling rotation of the substrate on the basis of detection of the laser mark and spraying an ultrasonic vibration-applied processing solution to the laser mark formed on the substrate.
According to another aspect of the present invention, there is provided a substrate processing apparatus for cleaning a laser mark formed on a surface of a substrate, characterized by comprising
holding/driving means for holding the substrate and rotating the substrate in a circumferential direction,
detection means for detecting a laser mark formed on the substrate in a non-contact manner indirectly or directly,
an ultrasonic nozzle arranged to face a surface of the substrate to spray an ultrasonic vibration-applied processing solution toward the substrate, and
control means for controlling rotation of the substrate held by the holding means on the basis of detection of the laser mark by the detection means, and cleaning the laser mark on the substrate with the processing solution sprayed from the ultrasonic nozzle.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.